However the term "Deuxième Bureau" (French: [døzjɛm byʁo]), like "MI6" and "KGB", outlived the original organization as a general label for the country's intelligence service.
The Deuxième Bureau was celebrated for its cryptanalytical work, but it was criticized for its involvement in the Dreyfus affair and its consistent overestimation of German military formations prior to World War II.
On June 8, 1871, the French Ministry of War authorized the creation of a service charged with performing "research on enemy plans and operations".
[1] The creation of a reworked Etat Major Général (or General Staff) came in response to the French loss in the Franco-Prussian War and acknowledgment of poor military planning structures in preparation for those hostilities.
In October 1894 the Dreyfus affair occurred and proved so politically divisive that, in May 1899, the government shifted responsibility for counter-espionage to the Ministry of the Interior.
With complete control of Interior Ministry funding, he created special counter-espionage units, the "brigades du Tigre", a reference to Clemenceau's nickname.
In February 1917, the Président du Conseil put a commissioner of the Sûreté Nationale in charge of the criminal police, general intelligence, and counter-espionage.
It scored a notable success at the outbreak of World War I when it cracked the German diplomatic cryptographic system.
These intercepts allowed an effective response to the movements of the German Army's 15 division-strong advances under Ludendorff at Montdidier and Compiègne, about 50 miles north of Paris.
Prior to World War II, a Deuxième Bureau agent codenamed 'Rex' made contact with Hans-Thilo Schmidt, a German cipher clerk, in the Grand Hotel of the Belgian town of Verviers.
Schmidt ultimately provided all the information necessary to crack the complex ciphers, which would play a key role in the Allied victory.
Raymond Arthur Schuhl, a French propagandist who had served in the 6th Section of the Deuxieme Bureau until the fall of France, became the OSS Chief of Morale Operations in Switzerland and was its principal forger through the war.